Oil and gas equipment and services provider FMC Technologies (NYSE: FTI) is a great company, plain and simple. The problem with great companies, though, is that they often face great expectations. By merely maintaining earnings guidance for the full year, it appears that the company let some people down.

There are a few factors at play here. For one, FMC is wrapping up some unusually profitable projects signed amid a more buoyant market environment. The company is still pulling in strong orders from customers including Petrobras (NYSE: PBR) and Statoil (NYSE: STO), but margins are headed down by 3% to 4% in the second half of the year. Management expects margins to trough sometime in 2011.

Another variable is the fallout from the Macondo oil disaster in the Gulf of Mexico. FMC is a global business, and derives only around 12% of sales from the Gulf. That said, there will definitely be some impact as a result of the moratorium on deepwater drilling. Management currently estimates a $100 million to $150 million hit to revenue in the back half of the year.

The Gulf situation is one key and fairly uncertain guidance variable. The other two are execution on subsea projects and the level of gas drilling activity. The latter has a direct impact on FMC's fluid control business, which provides hydraulic fracturing equipment to service firms like Schlumberger (NYSE: SLB) and Halliburton (NYSE: HAL). The recent strength in this market is actually what allowed FMC to maintain guidance, despite the hit from the deepwater moratorium.

With gas prices failing to respond to blazing summer temperatures, there is some question of whether the pace of drilling will continue. FMC investors should primarily be focused on the global pace of deepwater development, which so far looks largely unaffected by the Gulf disaster. The onshore scene is worth keeping an eye on, though.